How best to bump: Designing spaces to encourage conversation

Bumping spaces are places for those 'accidental encounters' to happen, but what's the best way to stimulate more of these (and more meaningful) conversations? 

Do these encounters need to coincide with natural traffic routes, or would a bespoke space allow 'bumping' to happen more frequently? 

Should bumping spaces be anchored around a need or interest (think 'men in sheds' schemes) or just the fact that people will be passing by frequently (think park bench)? Is it more appropriate for young, middle or older aged people? Do they have to be physical at all - or can we replicate a 'bump' digitally - like facebook are doing with the 'You've known this friend for X years' updates?

Nurture development have posted about the bumping habits of the Spanish - with their common plazas, well equipped with benches and places to stop and talk. I've seen first-hand how the same set up thrives in Peru, where immaculately groomed central plazas draw crowds, all chatting together in the evenings. The government maintains these areas at their cost, maybe because the potential benefits are difficult to ignore, maybe because groundwork salaries are cheap, or the fact it's expected to be a civic responsibility. Would we be willing to maintain bumping spaces, despite the obvious differences in culture and expectations? Could bumping spaces be made maintenance free? Urban splash simply designed one entrance corridor to lead people towards the bulding - people had to walk past each other every day, hopefully nodding, smiling and chatting as they went. 

We have a lot of questions about the value of bumping spaces - but we're approaching this concept through the lens of combating loneliness. The idea that shared, enjoyable spaces that encourage people to stop and chat - even if only for a little while - have a positive impact on those involved. 

We're keen to not repeat mistakes of the past, when our 'Winter Buddies' pilot (coordinating volunteers to visit older people during winter to help prevent falls and hospital admissions) actually made people lonelier when the pilot had stopped. Customers hadn't known the value of companionship until they'd had it, then had it taken away. That's why providing a space (physical or digital) appeals more than providing a service - for now anyway. 

So - what's the best way to progress the concept? I'm conflicted. 

With potentially weaker family ties, reducing physical and social mobility, more chance of being inactive digitally and living in close proximity to people of a similar age with whom to bump with - engaging residents at an older persons scheme seems to be an obvious starting point. 

Action here could be effective, sure, but is it lazy? The real challenge is designing something that can stimulate these micro conversations across the disparate ponds of society. That means people of different age, political preferences, social needs, incomes, ethnicity, interests and standpoints - all of whom could be experiencing profound loneliness.

It appears much trickier to bond groups who typically go out of their way to avoid each other e.g. I'm annoyed when there's children in the same cinema screen. Yet, would I stop and watch a locally produced movie in the middle of a main road - despite their being loads of kids about? Probably. With context, the bigger issue of cross-societal bumping doesn't seem so insurmountable.

I'm all ears - How would you use bump spaces in your community?